A study is carried out as to a case where a plurality of vehicles are traveling in the form of a vehicle group. When forming a vehicle group, the selection of vehicles forming the vehicle group or the order of the vehicles is important. In a device described in Patent Literature 1, vehicles forming a vehicle group are selected on the basis of vehicle information including the destination.    [Patent Literature 1] Japanese Unexamined Patent Application Publication No. 10-261195    [Patent Literature 2] Japanese Unexamined Patent Application Publication No. 2008-3675